Spray device

ABSTRACT

A spray device is provided in which a spray stem section is secured within a passage of a spray device body. The stem section is readily removable to allow easy cleaning and also is normally made of materials which allow disposal after use of the stem section. In order to allow such use of plastics materials, in particular the stem section is associated with the passage such that seal elements isolate feed ports over a relatively broad communication band to gutter channels in the stem section. Normally a nozzle combination is secured within a jet such that this combination is also separately disposable. The nozzle combination is held within the spray stem section using a spray hood.

The present invention relates to spray devices and more particularly tosuch spray devices utilised for. dispersing liquids such as paint orwood preservatives upon surfaces and structures.

Traditionally there are three general approaches to applying liquid suchas paints or preservatives to surfaces or structures. These approachesutilise brushes or rollers or a spray device in the form of a gun. Thepresent invention in particular relates to paint spray devices whichhave a number of advantages including more economical fluid distributionon the sprayed surface without brush or roller marks. However, paintspraying devices have a number of problems which have tended to limittheir widespread use in particular by amateur or domestic users.

One problem associated with paint spray devices is the frequent need toclean them after use and also that they can require frequent topping upwith paint. They can also put a strain on the user's hand particularlywhen a paint canister is full and attached to the spray gun head.

By their nature, spraying devices require accurate association betweenvarious components in order to achieve an appropriate spraydistribution. Such accurate association and reliability havenecessitated use of metal components to ensure a sufficient robustnessfor industrial use. These requirements for reliable and robustassociation for acceptability within the heavy usage environments ofcommercial and industrial applications have further exacerbated theacceptability of paint spray devices by amateur and domestic users. Itwill be understood that amateur and domestic users will generally havemuch smaller surface areas which require spray application and onlyrequire infrequent use.

In accordance with the present invention there is provided a spraydevice comprising projection means to generate a fluid spray projectionthrough a passage, a spray stem axially aligned within the passage toallow removal through an end of the passage, the stem includingisolation means such that, when aligned, respective feed ports in thepassage are isolated from one another and thereby fluid for the fluidspray projection may pass through at least one such feed port into thespray stem for spray projection out of a nozzle of the stem.

Typically, the isolation means comprises O ring seals about the stem.Typically, the O ring seals are secured within grooves formed in thestem. Generally, spacing between the isolation means defines anacceptable tolerance band width for association with respective feedports of the device.

Typically, the feed ports communicate with circumferential channelsformed in the stem. Normally, these circumferential channels includesink apertures connected to a jet. Normally the jet directly leads tothe nozzle and incorporates at least part of the means to generate afluid spray projection.

Typically, the projection means includes a piston. Normally, this pistonis electrically vibrated in order to stimulate spray projection.Generally, the piston is also axially removable from the spray stemeither with the spray stem from the passage or independently.

Generally, the spray stem and the passage are a close fit. Possibly, thespray stem and passage have reciprocal tapered or conical shaping.

Typically, the spray stem is secured to the passage at the end of thepassage. Normally the stem is secured to the passage through a screwthread engagement or bayonet fitting or using a retaining screw.

Normally the spray stem is made from a plastics material.

A separable spray stem containing the jet and spray projection mechanismmeans that the complete assembly can be made cheap enough to bediscarded, or a separate part could be provided to allow one to besoaking in cleaning fluid whilst the other is being used.

There are at present spraying devices which are hand held and attachedby a tube to a separate canister. There are also spray guns withcanisters attached. These devices can be expensive.

It would be advantageous to provide a method whereby the operator ofsuch products can have a cheap alternative and the versatility providedby a device which is also easy to clean, and may also have throw-awayparts as an alternative to cleaning should the operator decide todiscard them.

The main driving force of the spray device is provided by anelectrically operated vibrator which can use the mains electrical supplyor a battery.

The section containing the vibrator can have a handle fitted to the mainbody of the gun or it may be fitted on the fluid canister. This allowsit to be fitted to the top of a tin containing a suitably diluted liquidwhich will pass easily through a spray jet head, for example fenceprotective liquid. This reduces the necessity to keep frequently fillinga separate container which is usually attached to such spray guns. Italso reduces the need to have to clean containers after use.

To enable the vibrator mechanism to be fitted to the top of a tincontaining paint, a hole has to be made in the lid; this is done by theuse of a specially shaped spike which can be hammered or pushed into it.The bottom of the vibrator mechanism has a threaded section which isplaced through the hole and a collar is then screwed onto this when thelid has been removed. A rubber washer is used between the threadedsection and the collar to stop any leakage of paint and air. The sectionwhich is threaded has a piece shaped in the centre to allow a tube withfilter on the bottom to be pushed into it. Several tubes varying inlength with detachable filters can be provided to reach to the bottom oftins that vary in depth, or a flexible tube could be used.

An adapter to replace the jet spray assembly, which is fitted on thespray gun to allow a small bore tube to be fitted to it, and a handleequipped with a jet attached to the other end. The tube and handle canbe made cheap enough to throw away after use, and even the sectioncontaining the piston and jet assembly can be made cheap enough tothrowaway to alleviate the need for cleaning.

Should the need arise for a small quantity of paint to be used, this canstill be used in a separate container which has a handle attached to it,on the main body of the spray gun. To operate the vibrator when it isconnected to the mains or battery voltage supply, a switch is suitablypositioned on the side of the body containing it if the handle is on thejar. The switch is situated so that it can be suitably operated becausethe separate container's handle lines up with it. This is possiblebecause the section housing the vibrator mechanism has a section eitherside of it that protrudes and has holes through them. These line up withsections that protrude on the separate container; two screws are used tosecure them together and a rubber seal is fitted between to stop anyliquid which may be in the container from leaking out.

Embodiments of the present invention will now be described by way ofexample only, with reference to the accompanying drawings in which:

FIG. 1 is a side cross section of a spray device in accordance with thepresent invention;

FIG. 2 is a cross section of a spray stem with nozzle;

FIG. 3 is a side view of a spray stem component;

FIG. 4 is a side cross section of the spray stem illustrated in FIG. 3;

FIG. 5 is a schematic side view of a further spray device arrangement;

FIG. 6 is a schematic side view illustrating a piercing tool utilisedwith regard to a liquid container; and,

FIG. 7 illustrates a separate paint container vessel utilised with thearrangement depicted in FIG. 5.

There are at present spraying devices which are hand held and attachedby a tube to a separate canister. There are also spray guns withcanisters attached. These devices can be expensive.

It would be advantageous to provide a method whereby the operator ofsuch products can have a cheap alternative and the versatility providedby a device which is also easy to clean, and may also have throw-awayparts as an alternative to cleaning should the operator decide todiscard them.

The main driving force of the spray device is provided by anelectrically operated vibrator which can use the mains electrical supplyor a battery.

The section containing the vibrator can have a handle fitted to the mainbody of the gun or it may be fitted on the fluid canister. This allowsit to be fitted to the top of a tin containing a suitably diluted liquidwhich will pass easily through a spray jet head, for example fenceprotective liquid. This reduces the necessity to keep frequently fillinga separate container which is usually attached to such spray guns. Italso reduces the need to have to clean containers after use.

To enable the vibrator mechanism to be fitted to the top of a tincontaining paint, a hole has to be made in the lid; this is done by theuse of a specially shaped spike which can be hammered or pushed into it.The bottom of the vibrator mechanism has a threaded section which isplaced through the hole and a collar is then screwed onto this when thelid has been removed. A rubber washer is used between the threadedsection and the collar to stop any leakage of paint and air. The sectionwhich is threaded has a piece shaped in the centre to allow a tube withfilter on the bottom to be pushed into it. Several tubes varying inlength with detachable filters can be provided to reach to the bottom oftins that vary in depth, or a flexible tube could be used.

An adapter to replace the jet spray assembly, which is fitted on thespray gun to allow a small bore tube to be fitted to it, and a handleequipped with a jet attached to the other end. The tube and handle canbe made cheap enough to throw away after use, and even the sectioncontaining the piston and jet assembly can be made cheap enough tothrowaway to alleviate the need for cleaning.

Should the need arise for a small quantity of paint to be used, this canstill be used in a separate container which has a handle attached to it,on the main body of the spray gun. To operate the vibrator when it isconnected to the mains or battery voltage supply, a switch is suitablypositioned on the side of the body containing it if the handle is on thejar. The switch is situated so that it can be suitably operated becausethe separate container's handle lines up with it. This is possiblebecause the section housing the vibrator mechanism has a section eitherside of it that protrudes and has holes through them. These line up withsections that protrude on the separate container; two screws are used tosecure them together and a rubber seal is fitted between to stop anyliquid which may be in the container from leaking out.

There are at present spraying devices which are hand held and attachedby a tube to a separate canister. There are also spray guns withcanisters attached. These devices can be expensive.

FIG. 1 illustrates a spray gun 25, with the separate stem section 23screwed into it, and showing the three ‘O’ seal rings 26, 27, 28 inposition. A handle 30, is attached to the main body of the spray gun 25with a switch 31 fitted into it. A fluid or paint container 32 isscrewed onto the bottom of a body, of the spray gun 25.

The spray gun 25 is connected to the main electrical supply by the cable33, and plug head 34. It is then operated by pressing the switch 31,which operates a vibrator.

The spray device in the form of gun 25 operates by causing a vibratorassembly 100 to cause axial movement in the direction of arrowhead A ofa piston assembly secured within the separable spray stem 23. Electricalpower is provided to the vibration assembly 100 such that a contactfinger 101 oscillates to drive the piston spray projection propulsionmechanism within the stem section 23. Vibration of the mechanism causespiston movement within the jet 102 such that there is pressurisationwithin the container 2 which stimulates fluid, typically paint, flowinto the stem for further spray distribution. In these circumstances,the jet 102 within the stem section 23 includes feed ports 103, 104which respectively extend radially from that jet 102. Feed port 104 iscoupled to the interior of the container 32 in order to causepressurisation of the fluid 105. This pressurisation causes upflow offluid through a filter siphon 106 in order that paint is presentedthrough the feed port 103 to the stem jet 102. This fluid is thenfurther projected by the piston 106 through a nozzle 107 for spraydistribution. Use of piston vibration for spray distribution is knownand as described previously requires precision manufactured componentsin order to ensure that a piston and/or valve arrangement within the jetof the spray device achieved pressurisation of the container and alsopresentation of the fluid for spray distribution through a nozzle. Itwill be understood that such accuracy necessitates relatively hightolerance machining operations and use of mostly metal components whichrender previous arrangements unacceptable for disposal in view of theircosts. It will also be understood that when changing spray fluid type orat the end of a work period, it is necessary to clean down any spraydevice.

The present invention provides a separable stem section 23 which issecured within a passage of the gun body 25. The stem section 23 is madefrom relatively cheap plastics materials and so may be readily disposedof itself or at least a piston or nozzle combination core thrown awaywhilst, due to its easy removal and separation the remainder of the stemcan be cleaned.

The separable stem segment 23 is secured within a passage 110 throughscrew threads 123. Thus the stem section 23 is positioned along the sameaxial direction (arrowhead A) as that of the vibration mechanism 100acting through the finger 101 upon the piston propulsion mechanismwithin the jet 102. In order to avoid the necessity for accuratemachining, both of the screw thread 123 and positioning of the ports103, 104 relative to communication apertures in the stem 23 seals 26,27, 28 are provided with gutter channels 108, 109 between them. Theseseals 26, 27, 28 effectively isolate the gutter channels 108, 109whereby the feed port 104 for air compression within the canister 32 isisolated from the feed port 103 through which fluid such as paint ispresented to the jet 102 for propulsion through the nozzle 107.Normally, these seals 26, 27, 28 are O ring seal elements secured withingrooves of the stem section 23 such that they engage the interior wallof the passage formed in the gun body 25 in order to ensure the desiredisolation between the ports 103, 104. In such circumstances providedthere is at least partial overlap between the feed ports 103, 104 andthe gutter channels 108, 109, it will be understood that the necessaryfunctions of pressurisation within the canister 32 and paintpresentation to the jet 102 are achieved. Thus, there is no necessity toprovide accurate machining to ensure communication between the jet 102and feed ports 103, 104 as with previous spray devices. The necessityfor reduced accuracy therefore allows cast or rudimentarily machinedplastic material sections to be used for the stem 23 with the resultthat there is a radical reduction in manufacturing costs whereby thestem 23 may be considered disposable. Clearly, a disposable stem willnot require cleaning before further use.

FIG. 2 shows the separate stem section 23, which contains the piston andspraying assembly. As indicated above all of the section 23 can be madecheaply enough to throw away if necessary. The assembly has screwthreads 24, on the outside to allow it to be secured into a passage of amain body of the spray gun 25, shown in FIG. 1. The screw threads 24engage screw threads 23 of the passage 110 from in the body 25 inFIG. 1. On the outside of the section 23, three O ring seals 26, 27, 28are fitted. These seals 26, 27, 28 are there to keep the ports 103, 104of the spray guns separated and isolated. On the end of the separatesection 23, a jet nozzle assembly or combination 29, is screwed on. Thisassembly 29 can be replaced if required by an adaptor so that a tube 9in FIG. 5 below can be attached.

As indicated above, a finger 101 vibrates in the axial directionindicated by arrowheads A in order that through an oscillating actioncontrolled by a spring 111, a piston valve 109 acts to create thepressurisation through the port 104 and stimulates fluid flow in acavity 112 fed through the port 103. A regulating plug 113 is providedin the jet 102 in order that only when pressurisation in the cavity 12is sufficient to overcome a spring 1 14 bias for the plug 1 13 willfluid flow along the jet 102 and out of the nozzle 107. In short,pressurisation of the fluid within the cavity 1 12 displaces the plug113 such that fluid bypasses that plug 1 13 into the jets 112 andthereafter out of the nozzle 107. The plug 113 also helps retainpressure within the canister 32.

In the above circumstances it will be appreciated that the part of thestem section 23 which is most wetted by the fluid is the jet 102 andnozzle 107. There is limited liquid in the cavity 112 and feed port 103.In such circumstances it is convenient for a nozzle hood 115 to bedetachable through a screw thread 1 16 such that the nozzle 107, spring114 and plug 113 may be removed as a combination for disposal wherebythe other parts, that is to say the remainder of the stem 23 and nozzlehood 115 may be cleaned. Such cleaning may be through soaking orotherwise. In such circumstances the remainder of the stem 23 can beeasily cleaned or disposed of if the cavity 112 retains fluid which isdifficult to remove such as thick paints, etc. Clearly upon reassemblyif the nozzle 107, spring 114 and plug 113 are disposed of then a newsuch combination will be inserted within the stem 23 for subsequentoperations of the spray device.

FIGS. 3 and 4 illustrate stem section 23 in isolation respectively as aside view and side cross section. Thus, a screw thread 123 is providedto secure the stem 23 in the passage of a spray device housing. Noduleelements 116 of a collar part 117 help to allow manual rotation in orderto provide securing through the screw threads 123. The stem 23incorporates gutter channels 108, 109 as indicated previously tofacilitate communication with feed ports 103, 104 (FIGS. 1 and 2). Sinkapertures 118, 119 are provided within these gutter channels 108, 109.The apertures 118, 119 have an acceptable circumferential spacingwhereby a communication pathway between the jet 102 of the stem 23 andthe respective feed ports 103, 104 is provided to ensure pressurisationof the canister 32 (not shown) and presentation of fluid such as paintthrough the feed port 103 for spray distribution as describedpreviously. Within the outer surface of the circumferential wall of thestem 23, grooves 120, 121, 122 are provided to accommodate isolationseals as described previously as O ring seals 26, 27, 28 with regard toFIGS. 1 and 2. In such circumstances within a stem passage 110 theseseal elements (26, 27, 28) ensure isolation between the feed ports (103,104), sink apertures 118, 119 and the gutter channels 108, 109 whilstalso ensuring an acceptable axial communication overlap range for goodcommunication between these features in order to reduce the necessityfor assembly accuracy, etc.

Within the stem 23 as indicated previously a jet 102 is provided forcommunication with the nozzle 107 (FIGS. 2 and 3). It will beappreciated that this jet 102 extends along the major longitudinal axisof the stem 23 defined by X-X in FIGS. 3 and 4. This axis X-X is alsothe centre axis of the passage 110 within which the stem 23 is secured.Removal of the stem 23 as indicated is by longitudinal axialdisplacement out of an open end of that passage 110 (FIGS. 1 and 2).Similarly assembly is through location within that passage 110. Normallylocation is through a screw thread assembly but it will be appreciated abayonet fitting or other appropriate securing mechanism could be used,such as a retaining radial grub screw.

As indicated above the nozzle combination of nozzle 107, spring 114 andplug 113 is generally secured within the jet 102. Retention of thisnozzle combination is provided by a shoulder engagement between the plug113 and a part 43 of the jet 102 at one end and by constriction by anozzle hood 115 at the other (FIGS. 1 and 2). This nozzle (107, 114,113) combination is readily disposable even if the stem 23 itself isrepeatedly used. It will be appreciated that the nozzle 107 willnormally incorporate grooves and possible perforations through which thespray dispersion is propelled as required. In such circumstances theparticular nozzle utilised in terms of groove dimensions, sizing andgrading can be changed as required for different paint or fluid types ordesired spray distribution.

One desirable feature of the present invention is to provide a spraystem section 23 and/or nozzle combination (107, 113, 114) which issufficiently cheaply manufactured and assembled that it is readilydisposable. In such circumstances these components are generally madefrom a plastics material cast to the appropriate shape in a mould.Inaccuracies in fabrication can be accommodated by the broad acceptableaxial band or communication gap provided by the gutter channels 108, 109in the stem to the sink apertures 118, 119 with isolation providedthrough the seal elements 26, 27, 28. Alternatively a spray stem inaccordance with the present invention may take a tapered or conicalconfiguration narrowing from the nozzle end which is forced into slightcompression within the passage by the screw thread or other means ofsecuring the stem section in the passage. In such circumstances, thetapered association between the stem section and the passage will causeseal isolation between the respective feed ports and sink apertures inthe gutter grooves of the stem section. A compressive taperconfiguration may therefore allow the use of a stem section which doesnot incorporate specific seal elements such as O ring seals forisolation between the feed parts.

Also in accordance with the present invention there is provided a spraydevice arrangement as depicted in FIGS. 5 to 7. Thus, as shown in FIG. 5a spray propulsion section 1, contains a vibrator and a pump mechanismattached to a tin of paint 2, using a collar 3, which is threaded onto asection of the section 1, which has been passed through a hole in thelid 4, and is also threaded to accept it. A tube 20, attached to it,with a filter 21, on the end, and this passes down into the bottom ofthe liquid in the tin 2.

Thus paint removed from the tin 2 is forced by pressurisation within thetin 2 upwards through the tube 20 into the vibrator and pump mechanismwithin the section 1 and thence onward through a feed pipe 9 to a sprayhead nozzle 11 in order to present a spray distribute 12 as shown. Inorder to retain such pressurisation the lid 4 is secured by some form ofretainer to prevent pressurised detachment from the tin 2. Typically ahandle 10 is provided to allow appropriate manipulation of the spraydistribution 2 for fluid or paint coverage, etc. The vibrator within thesection 1 operates in accordance with known principles utilisingelectrical power provided through a cable 13 and plug 14 secured to apower supply (not shown). A switch 22 operates to switch on and off thevibrator and therefore stimulate spray distribution 12. Alternatively, awireless control switch could be secured to the handle 10 so thatoperation of the section 1 may be remotely controlled.

With the arrangement depicted in FIG. 5 it will be appreciated that anoperator is only encumbered with the handle 10 and nozzle 11 combinationrather than the weight of the vibration and pump mechanism secured tothe tin 2. Thus, the user is subject to less work fatigue when operatingthe arrangement.

FIG. 6 illustrates use of a tool in order to gain access to the tin ofpaint 2. The tool 5 has a spike on an end 6. This spike is eitherhammered or pressed into the lid 7, of the tin of paint 2, to create ahole for the threads on the shaped section 1, (FIG. 5), to fit therethrough and then be held in position by the collar 3. The hole allowsair to the tin 2 as well as paint out so that the tin 2 is pressurisedby air entering the tin 2 whereby paint is forced out. The tool 5 has asection 8 which protrudes around its circumference to prevent it beingdriven too deeply into the lid, 7.

Attached to one end of the shaped section 1, (FIG. 5), is a flexibletube 9, the other end of the tube (12) is fitted to the handle 10, whichis hollow to allow the liquid to pass up into a nozzle jet 11, which isscrewed onto its end. The liquid from the tin of paint 2, can then passfrom the tin 2 when the vibrator has been connected to the electricsupply, it will then provide the spray distribution 12, out of thenozzle 11.

As indicated normally the arrangement connects the vibrator to a mainselectrical supply through the cable 13, with a suitable plug 14. Theswitch 22, FIG. 5 is used to switch the electrical supply on or off.Alternatively, battery power could be used.

FIG. 7 shows a separate container 15, for use when paint has to bethinned before use in accordance with the arrangement shown in FIG. 5.The shaped section 1, FIG. 5, has flanges 16, which protrude either sidewith holes through-them. When the separate section 1, is placed on thetop of the separate container 15, these line up with flanges 17, whichhave holes in them and are threaded. Two screws 18, are used to securethem together, a rubber washer 19, stops any leakage.

Whilst endeavouring in the foregoing specification to draw attention tothose features of the invention believed to be of particular importanceit should be understood that the Applicant claims protection in respectof any patentable feature or combination of features hereinbeforereferred to and/or shown in the drawings whether or not particularemphasis has been placed thereon.

1-27. (canceled)
 28. A spray device comprising projection means togenerate a fluid spray projection through a passage, a spray stemaxially aligned within the passage to allow removal through an end ofthe passage. The stem including isolation means such that, when aligned,respective feed ports in the passage are isolated from one another andthereby fluid for the fluid spray projection may pass through at leastone such feed port into the spray stem for spray projection out of anozzle of the stem.
 29. A device as claimed in claim 28 wherein theisolation means comprises O ring seals about the stem.
 30. A device asclaimed in claim 29 wherein the O ring seals are secured within groovesformed in the stem.
 31. A device as claimed in claim 28 wherein spacingbetween the isolation means defines an acceptable tolerance band widthfor association with respective feed ports of the device.
 32. A deviceas claimed in claim 28 wherein the feed ports communicate withcircumferential channels formed in the stem.
 33. A device as claimed inclaim 32 wherein these circumferential channels include sink aperturesconnected to a jet.
 34. A device as claimed in claim 33 wherein the jetdirectly leads to the nozzle and incorporates at least part of the meansto generate a fluid spray projection.
 35. A device as claimed in claim28 wherein the project means includes a piston.
 36. A device as claimedin claim 35 wherein this piston is electrically vibrated in order tostimulate spray projection.
 37. A device as claimed in claim 35 whereinthe piston is axially removable from the spray stem either with thespray stem from the passage or independently.
 38. A device as claimed inclaim 28 wherein the spray stem and the passage are a close fit.
 39. Adevice as claimed in claim 28 wherein the spray stem and passage havereciprocal tapered or conical shaping.
 40. A device as claimed in claim28 wherein the spray stem is secured to the passage at the end of thepassage.
 41. A device as claimed in claim 28 wherein the stem is securedto the passage through a screw thread engagement or bayonet fitting orusing a retaining screw.
 42. A device as claimed in claim 28 wherein thespray stem is made from a plastics material.
 43. A spray arrangement inwhich a spray propulsion section is secured to a fluid container inorder to generate through vibration action propulsion of a fluid spraythrough a tube conduit to a spray nozzle which may be held remotely fromthe spray propulsion section.
 44. An arrangement as claimed in claim 43wherein the spray propulsion section includes a vibrator and a pumpmechanism to propel fluid through the tube conduit to the spray headnozzle.
 45. An arrangement as claimed in claim 43 wherein an operatingswitch for the arrangement is located upon the spray propulsion section.46. An arrangement as claimed in claim 43 wherein a wireless switch isattached to a handle of the nozzle in order to allow remote control ofthe spray propulsion section.
 47. An arrangement as claimed in claim 43wherein the spray head nozzle is readily detached from the tube conduitfor cleaning or disposal.
 48. A tool for providing access to a fluidcontainer incorporating a spike at one end in order to create anaperture upon which a spray propulsion section of an arrangement asclaimed in claim 43 can be secured.
 49. A fluid container incorporatingreciprocal flange elements to accept a spray propulsion section of anarrangement as claimed in claim 43 such that pressurization of thatcontainer is readily achieved for propulsion of fluid retained withinthe container.